AAT1272IWO-T1

LED照明驱动器 1.5A Boost Current Regulator

The AAT1272 is a high-efficiency, high-current boost converter capable of 1.5A typical output current. It is an ideal power solution for LED photo flash applications in all single cell Li-ion powered products. The AAT1272 maintains output current regulation by switching the internal high-side and low-side switch transistors. The transistor switches are pulse-width modulated at a fixed frequency of 2MHz. The high switching frequency allows the use of a small inductor and output capacitor, making the AAT1272 ideally suited for small battery-powered applications. An industry-standard I²C serial digital input is used to enable, disable and set the movie-mode current for each flash LED with up to 16 movie-mode settings. The AAT1272 also includes a separate Flash Enable input to initiate both the flash operation and the default timer, which can be used either to terminate a flash event at the end of a user-programmed delay or as a safety feature. The maximum flash and movie-mode current is set by one external resistor; the ratio of Flash to Movie-mode current is set at approximately 7.3:1. One or two LEDs can be connected to the AAT1272; in the case of two LEDs the output current is matched between each diode. The AAT1272 contains a thermal management system to protect the device in the event of an output short-circuit condition. Built-in circuitry prevents excessive inrush current during start-up. The shutdown feature reduces quiescent current to less than 1.0µA. The AAT1272 is available in a Pb-free, thermally-enhanced 14-pin 3x3mm TDFN package.